Revert "Create const block DefIds in typeck instead of ast lowering"

This reverts commit ddc5f9b.

Author: oli-obk

compiler/rustc_ast/src/ast.rs

@@ -1392,7 +1392,7 @@ pub enum ExprKind {
     /// An array (e.g, `[a, b, c, d]`).
     Array(ThinVec<P<Expr>>),
     /// Allow anonymous constants from an inline `const` block
-    ConstBlock(P<Expr>),
+    ConstBlock(AnonConst),
     /// A function call
     ///
     /// The first field resolves to the function itself,

compiler/rustc_ast/src/mut_visit.rs

@@ -1411,7 +1411,7 @@ pub fn noop_visit_expr<T: MutVisitor>(
     match kind {
         ExprKind::Array(exprs) => visit_thin_exprs(exprs, vis),
         ExprKind::ConstBlock(anon_const) => {
-            vis.visit_expr(anon_const);
+            vis.visit_anon_const(anon_const);
         }
         ExprKind::Repeat(expr, count) => {
             vis.visit_expr(expr);

compiler/rustc_ast/src/visit.rs

@@ -954,7 +954,7 @@ pub fn walk_expr<'a, V: Visitor<'a>>(visitor: &mut V, expression: &'a Expr) -> V
         ExprKind::Array(subexpressions) => {
             walk_list!(visitor, visit_expr, subexpressions);
         }
-        ExprKind::ConstBlock(anon_const) => try_visit!(visitor.visit_expr(anon_const)),
+        ExprKind::ConstBlock(anon_const) => try_visit!(visitor.visit_anon_const(anon_const)),
         ExprKind::Repeat(element, count) => {
             try_visit!(visitor.visit_expr(element));
             try_visit!(visitor.visit_anon_const(count));

compiler/rustc_ast_lowering/src/expr.rs

@@ -74,7 +74,14 @@ impl<'hir> LoweringContext<'_, 'hir> {
 
             let kind = match &e.kind {
                 ExprKind::Array(exprs) => hir::ExprKind::Array(self.lower_exprs(exprs)),
-                ExprKind::ConstBlock(c) => hir::ExprKind::ConstBlock(self.lower_expr(c)),
+                ExprKind::ConstBlock(c) => {
+                    let c = self.with_new_scopes(c.value.span, |this| hir::ConstBlock {
+                        def_id: this.local_def_id(c.id),
+                        hir_id: this.lower_node_id(c.id),
+                        body: this.lower_const_body(c.value.span, Some(&c.value)),
+                    });
+                    hir::ExprKind::ConstBlock(c)
+                }
                 ExprKind::Repeat(expr, count) => {
                     let expr = self.lower_expr(expr);
                     let count = self.lower_array_length(count);

compiler/rustc_ast_lowering/src/index.rs

@@ -236,6 +236,14 @@ impl<'a, 'hir> Visitor<'hir> for NodeCollector<'a, 'hir> {
         });
     }
 
+    fn visit_inline_const(&mut self, constant: &'hir ConstBlock) {
+        self.insert(DUMMY_SP, constant.hir_id, Node::ConstBlock(constant));
+
+        self.with_parent(constant.hir_id, |this| {
+            intravisit::walk_inline_const(this, constant);
+        });
+    }
+
     fn visit_expr(&mut self, expr: &'hir Expr<'hir>) {
         self.insert(expr.span, expr.hir_id, Node::Expr(expr));
 

compiler/rustc_ast_pretty/src/pprust/state/expr.rs

@@ -380,9 +380,8 @@ impl<'a> State<'a> {
             ast::ExprKind::Array(exprs) => {
                 self.print_expr_vec(exprs);
             }
-            ast::ExprKind::ConstBlock(expr) => {
-                self.word_space("const");
-                self.print_expr(expr, FixupContext::default());
+            ast::ExprKind::ConstBlock(anon_const) => {
+                self.print_expr_anon_const(anon_const, attrs);
             }
             ast::ExprKind::Repeat(element, count) => {
                 self.print_expr_repeat(element, count);

compiler/rustc_const_eval/src/const_eval/fn_queries.rs

@@ -38,6 +38,7 @@ fn constness(tcx: TyCtxt<'_>, def_id: LocalDefId) -> hir::Constness {
     match node {
         hir::Node::Ctor(_)
         | hir::Node::AnonConst(_)
+        | hir::Node::ConstBlock(_)
         | hir::Node::ImplItem(hir::ImplItem { kind: hir::ImplItemKind::Const(..), .. }) => {
             hir::Constness::Const
         }
@@ -56,7 +57,6 @@ fn constness(tcx: TyCtxt<'_>, def_id: LocalDefId) -> hir::Constness {
             if is_const { hir::Constness::Const } else { hir::Constness::NotConst }
         }
         hir::Node::Expr(e) if let hir::ExprKind::Closure(c) = e.kind => c.constness,
-        hir::Node::Expr(e) if let hir::ExprKind::ConstBlock(_) = e.kind => hir::Constness::Const,
         _ => {
             if let Some(fn_kind) = node.fn_kind() {
                 if fn_kind.constness() == hir::Constness::Const {

compiler/rustc_hir/src/hir.rs

@@ -1623,6 +1623,14 @@ pub struct AnonConst {
     pub span: Span,
 }
 
+/// An inline constant expression `const { something }`.
+#[derive(Copy, Clone, Debug, HashStable_Generic)]
+pub struct ConstBlock {
+    pub hir_id: HirId,
+    pub def_id: LocalDefId,
+    pub body: BodyId,
+}
+
 /// An expression.
 #[derive(Debug, Clone, Copy, HashStable_Generic)]
 pub struct Expr<'hir> {
@@ -1909,7 +1917,7 @@ pub fn is_range_literal(expr: &Expr<'_>) -> bool {
 #[derive(Debug, Clone, Copy, HashStable_Generic)]
 pub enum ExprKind<'hir> {
     /// Allow anonymous constants from an inline `const` block
-    ConstBlock(&'hir Expr<'hir>),
+    ConstBlock(ConstBlock),
     /// An array (e.g., `[a, b, c, d]`).
     Array(&'hir [Expr<'hir>]),
     /// A function call.
@@ -3641,6 +3649,7 @@ pub enum Node<'hir> {
     Variant(&'hir Variant<'hir>),
     Field(&'hir FieldDef<'hir>),
     AnonConst(&'hir AnonConst),
+    ConstBlock(&'hir ConstBlock),
     Expr(&'hir Expr<'hir>),
     ExprField(&'hir ExprField<'hir>),
     Stmt(&'hir Stmt<'hir>),
@@ -3701,6 +3710,7 @@ impl<'hir> Node<'hir> {
             Node::PreciseCapturingNonLifetimeArg(a) => Some(a.ident),
             Node::Param(..)
             | Node::AnonConst(..)
+            | Node::ConstBlock(..)
             | Node::Expr(..)
             | Node::Stmt(..)
             | Node::Block(..)
@@ -3798,6 +3808,7 @@ impl<'hir> Node<'hir> {
             }
 
             Node::AnonConst(constant) => Some((constant.def_id, constant.body)),
+            Node::ConstBlock(constant) => Some((constant.def_id, constant.body)),
 
             _ => None,
         }
@@ -3866,6 +3877,7 @@ impl<'hir> Node<'hir> {
         expect_variant,       &'hir Variant<'hir>,      Node::Variant(n),      n;
         expect_field,         &'hir FieldDef<'hir>,     Node::Field(n),        n;
         expect_anon_const,    &'hir AnonConst,          Node::AnonConst(n),    n;
+        expect_inline_const,  &'hir ConstBlock,         Node::ConstBlock(n),   n;
         expect_expr,          &'hir Expr<'hir>,         Node::Expr(n),         n;
         expect_expr_field,    &'hir ExprField<'hir>,    Node::ExprField(n),    n;
         expect_stmt,          &'hir Stmt<'hir>,         Node::Stmt(n),         n;

compiler/rustc_hir/src/intravisit.rs

@@ -344,6 +344,9 @@ pub trait Visitor<'v>: Sized {
     fn visit_anon_const(&mut self, c: &'v AnonConst) -> Self::Result {
         walk_anon_const(self, c)
     }
+    fn visit_inline_const(&mut self, c: &'v ConstBlock) -> Self::Result {
+        walk_inline_const(self, c)
+    }
     fn visit_expr(&mut self, ex: &'v Expr<'v>) -> Self::Result {
         walk_expr(self, ex)
     }
@@ -716,14 +719,22 @@ pub fn walk_anon_const<'v, V: Visitor<'v>>(visitor: &mut V, constant: &'v AnonCo
     visitor.visit_nested_body(constant.body)
 }
 
+pub fn walk_inline_const<'v, V: Visitor<'v>>(
+    visitor: &mut V,
+    constant: &'v ConstBlock,
+) -> V::Result {
+    try_visit!(visitor.visit_id(constant.hir_id));
+    visitor.visit_nested_body(constant.body)
+}
+
 pub fn walk_expr<'v, V: Visitor<'v>>(visitor: &mut V, expression: &'v Expr<'v>) -> V::Result {
     try_visit!(visitor.visit_id(expression.hir_id));
     match expression.kind {
         ExprKind::Array(subexpressions) => {
             walk_list!(visitor, visit_expr, subexpressions);
         }
         ExprKind::ConstBlock(ref const_block) => {
-            try_visit!(visitor.visit_expr(const_block))
+            try_visit!(visitor.visit_inline_const(const_block))
         }
         ExprKind::Repeat(ref element, ref count) => {
             try_visit!(visitor.visit_expr(element));

compiler/rustc_hir_analysis/src/check/region.rs

@@ -407,14 +407,11 @@ fn resolve_expr<'tcx>(visitor: &mut RegionResolutionVisitor<'tcx>, expr: &'tcx h
     match expr.kind {
         // Manually recurse over closures and inline consts, because they are the only
         // case of nested bodies that share the parent environment.
-        hir::ExprKind::Closure(&hir::Closure { body, .. }) => {
+        hir::ExprKind::Closure(&hir::Closure { body, .. })
+        | hir::ExprKind::ConstBlock(hir::ConstBlock { body, .. }) => {
             let body = visitor.tcx.hir().body(body);
             visitor.visit_body(body);
         }
-        hir::ExprKind::ConstBlock(expr) => visitor.enter_body(expr.hir_id, |this| {
-            this.cx.var_parent = None;
-            resolve_local(this, None, Some(expr));
-        }),
         hir::ExprKind::AssignOp(_, left_expr, right_expr) => {
             debug!(
                 "resolve_expr - enabling pessimistic_yield, was previously {}",